This little snippet will make your button open up like a book on hover. There are 2 variations one in which the button open us from the leftmost end and shows a longer message and the other one where the button maintains the size and opens up from the center. These were designed by Hornebom
If you are having trouble with the pen, try the archived copy on GitHub
See the Pen Folding Button by Hornebom (@Hornebom) on CodePen.0